1. Field of the Invention
The invention relates to a device for externally fixing and/or imparting traction to the cervical spine and including a fastening ring attached to the patient's head and a plurality of outwardly projecting fastening bearings, a plurality of support bearings attached in the patient's chest and/or back region and a plurality of connecting rods which connect the fastening and support bearings and are provided with connecting and support bearing ball joints which are connected with the connecting rods by means of clamping elements.
2. Brief Description of the Prior Art
A device of the abovedescribed type is known and is employed, for example, to attach a fixing and traction-imparting halo used in the treatment of diseases of the cervical spine. The device includes a fastening ring which is attached to the patient's head at the level of the forehead and is provided with a plurality of bores for receiving pressure plates disposed between the patient's head and the fastening ring and for receiving laterally outwardly projecting fastening bearings. In the patient's chest and/or back region, support bearings are attached preferably to a supporting bandage or a supporting vest pulled over the upper body of the patient to be treated and are connected with the fastening bearings at the fastening ring by connecting rods. These connecting rods may be adjustable in length so that, if required, the cervical spine can be fixed as well as put into traction.
Customarily, the fastening bearings are composed of conical pins which project horizontally from the fastening rings while the support bearings are composed of cylindrical pins projecting vertically from corresponding fastening plates. The connection between the connecting rods and the fastening bearings and the support bearings is effected by two clamps which are rotatable opposite to one another in order to equalize the sides and receive, on the one hand, the pin of the fastening or support bearing and, on the other hand, the respective connecting rod, while, after aligning the device and applying the necessary traction force, they connect the rods and pins together in a force-locking manner.
Although the mutually oppositely rotatable clamps for producing the force-locking connection between the pins of the fastening and support bearings on the one hand and the connecting rods on the other hand provide for a sloped connection between the fastening bearings and the support bearings, their structure is complicated and thus expensive and, due to their limited adjustability, the treating physician has difficulties in adjusting them and aligning them in such a manner that no bending stresses act on the connecting rods which would be disadvantageous for the patient.